Geometric toy construction system

ABSTRACT

A geometric model construction system comprised of a variety of shape elements. These shape elements are connected to each other along edges by connector strip parts in a hinged, sliding union. This union allows a full continuous range of angular positions between adjacent shape elements. Polyhedra and other geometric forms may be easily built up by joining connector strips onto multiple shape elements. These shape elements may be flat or curved polygons of a sheet material ( 10 ) or may be skeletal wire frame elements ( 12 ). Hinged sliding joints between shape elements and connector strips are accomplished with hinge-leaf ( 30 ) and hinge-pivot features ( 42 ). Female features of c-shaped cross-section are designed to admit and grip male features of circular cross-section along shape element edges ( 14 ). Finished models may be easily disassembled and parts reused. They are also suitable for long term display, and will not degrade over time.

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] Not applicable.

[0002] 1. Field of Invention

[0003] This system relates to educational toy geometric models, specifically to an improved method of construction.

[0004] 2. Description of Related Art

[0005] There are numerous prior art construction systems intended to enable the formation of two and three-dimensional geometric models. These use a variety of uniquely shaped and configured building elements. Many systems have been created and marketed as toys for amusement and educational purposes. They make use of basic principles of construction and geometry to teach in a diverting and amusing fashion. The principles behind geometric relationships occur repeatedly in nature. Their use in an educational setting helps develop a deeper understanding of naturally occurring structures. These toys create a sense of how geometric shapes and spaces interact. The groundwork is laid to a more meaningful understanding of diverse subjects. How atoms arrange themselves in molecules and crystals, to the symmetries of a sunflower blossom, to the principles of construction engineering are elucidated.

[0006] Various solid geometric shapes may take the form of traditional block sets. In these systems elements simply stack one on another. Snap together construction block type elements (marketed under trade names such as Lego, Duplo, etc.) may be connected to each other by various means. These types of block systems are described in U.S. Pat. Nos. 176,144 (McDougall 1876), 2,509,669 (Borst 1950), 2,786,301 (Torricelli 1957), 2,791,868 (Viken 1957), 2,861,388 (Favarefto 1958), 2,885,822 (Onanian 1959), 2,984,935 (Beck 1961), 3,177,611 (Beck 1965), 3,367,063 (Bondesen 1968), 3,415,007 (Howe 1968), 3,442,044 (Quercetti 1969), 3,496,670 (Sloop 1970), 3,523,384 (Adelsohn 1970), 3,550,310 (Bock-Greissau 1970), 3,597,872 (Vennola 1971), 3,597,858 (Ogsbury 1971), 3,597,874 (Ogsbury 1971), 3,597,875 (Christiansen 1971), 3,611,620 (Perry 1971), 3,648,404 (Ogsbury 1972), 3,672,681 (Wolfe 1972), 3,681,870 (Alpert 1972), 3,726,027 (Cohen 1973), 3,777,393 (Baer 1973), 3,811,682 (Neale 1974), 3,815,280 (Gilfillan 1974), 3,831,503 (Tranquillitsky 1974), 3,854,255 (Baker 1974), 3,867,784 (Lange 1975), 3,924,376 (Tsurumi 1975), 3,940,142 (Hinz 1976), 4,077,154 (Muller 1978), 4,090,322 (Hakel978), 4,114,307 (Liebeskind 1978), 4,209,934 (Ogawa 1980), 4,227,334 (Hooker 1980), 4,253,268 (Mayr 1981), 4,345,761 (China 1982), 4,456,258 (Lodrick 1984), 4,509,930 (Schweigert 1985), 463,360 (Brasch 1987), 4,682,450 (Diamond 1987), 4,822,315 (Ben-Gal 1989), 4,875,681 (Ofir 1989), 5,106,093 (Engel 1992), 5,302,148 (Heinz 1994) and 5,538,452 (Kurani 1996). These systems generally lack the flexibility to create new geometric forms such as polyhedra from a core set of construction elements. The systems comprised of model forms that are complete to begin with provide limited opportunity to learn through interaction.

[0007] Hub and strut construction sets involve linear stick-like members. These plug into or fasten to mating holes formed at various angles in hub members. They are marketed under a variety of trade names including Tinker Toy, Erector and Ramagon. These systems have been devised to enable the building of more or less open lattice type space frame structures, as described in U.S. Pat. Nos. 1,870,978 (Wolfe 1932), 2,208,049 (Pajeau 1940), 2,313,357 (Pajeau 1943), 2,410,874 (Greenberg 1946), 2,410,875 (Segal 1946), 2,414,716 (Carson 1947), 2,709,318 (Benjamin 1955), 3,201,894 (Resch 1965), 3,415,008 (Fischer 1968), 3,486,268 (Fischer 1969), 3,510,962 (Sato 1970), 3,510,979 (Fischer 1970), 3,577,660 (Kenney 1971), 3,600,825 (Pearce 1971), 3,722,153 (Baer 1973), 3,803,754 (Fischer 1974), 3,891,335 (Feil 1975), 4,051,621 (Hogan 1977), 4,084,344 (Asano 1978), 4,129,975 (Gabriel 1978), 4,159,592 (Gabriel 1979), 4,271,628 (Barlow 1981), 4,274,222 (Zahn 1981), 4,326,354 (Hagberg 1982), 4,348,830 (Hagberg 1982), 4,474,490 (Harper 1984), 4,492,723 (Chadwick 1985), 4,701,131 (Hildebrandt 1987), 4,738,648 (Berndt 1988), 4,838,003 (Zeigler 1989), 4,904,108 (Wendel 1990), and 4,911,672 (Erickson 1990), 5,046,982 (Erickson 1991). These systems generally limit the variety of models that can be created. Strut lengths are fixed and the angles formed between struts are fixed by the design of the hubs.

[0008] Planar polygon type construction systems comprise another category of geometric construction sets. Kits of this type are marketed under the trade names of Polydron, Googolplex, Linxx, Waffle, Snapland, etc. They enable relatively flat planar geometric shapes to be connected edgewise either parallel to or perpendicular to the longitudinal axis of the shape's edge. The toy geometric construction system described herein is an improved version of this general category. Various existing planar polygon construction systems are further described as follows:

[0009] Paper and scissors systems involve the construction of models through the careful cutting and folding of paper or card material. Faces are attached to each other along edges with glue, tape, or elastic bands. These systems are described in the books Mathematical Recreations and Essays (Ball & Coxiter ISBN 0486253570 pp:153), Mathematical Models (Cundy & Rollett ISBN 0906212200 pp:76-159), Polyhedron Models (Wenninger ISBN 0521098599 pp:all), Adventures Among the Torroids (Stuart ISBN 0686119363 pp:all) and in U.S. Pat. Nos. 1,292,188 (Wheeler 1919), 3,654,375 (Geiger 1972), 3,971,156 (Lamlee 1976), and 4,380,133 (Arnstein 1983).These methods are popular in school classrooms due to the minimal cost and availability of supplies. However, the resulting models are extremely susceptible to physical damage, and degradation over time. Also, the successful construction of a paper model often requires a level of precision and dexterity beyond the abilities of many individuals.

[0010] Tine and tube systems involve substantially flat panels of various geometric shapes. Short tubes connect with mating slots or similar means. These are described in U.S. Pat. Nos. 3,554,382 (Grinbergs 1971), 4,065,220 (Ruga 1977), and 4,728,310 (Valtolina 1988). These systems have the disadvantage of requiring faces to be at specified fixed angles to each other (typically 90 degrees). The designed placement and orientation of the mating slots determine these angles.

[0011] Similarly, some edge to edge connection systems require predetermined fixed angles between elements. This severely restrict the number and variety of geometric forms that may be constructed. The systems described in the following U.S. Pat. Nos. all suffer from these limitations. 1,193,975 (Beardsley 1916), 1,870,539 (Warner 1932), 1,883,214 (Wilson 1932), 2,454,307 (Cooley 1948), 2,708,329 (McKee 1955), 3,032,919 (Amsler 1962), 3,066,436 (Schuh 1962), 3,086,629 (Blitzer 1963), 3,537,706 (Heavener 1970), 3,570,169 (Jacob 1971), 3,827,177 (Wengel 1974), 3,968,882 (Mello 1976), 3,987,580 (Ausnit 1976), 4,073,105 (Daugherty 1978), 4,147,007 (Eppich 1979), 4,257,207 (Davis 1981), 4,270,302 (Dandia 1981), 4,334,868 (Levinrad 1982), 4,345,762 (Lebelson 1982), 4,493,425 (Yoshida 1985), 4,685,892 (Gould 1987), 4,789,370 (Ellefson 1988), 4,793,725 (Cheng 1988), 4,856,928 (Savale 1989), 4,874,341 (Ziegler 1989), 5,121,526 (Burkard 1992), 5,137,486 (Gluckman 1992), 5,400,918 (Prodaniuk 1995), and 5,628,154 (Gavette 1997).

[0012] Some edge to edge connection systems use elastic bands to hold faces together. These are described in U.S. Pat. Nos. 3,120,078 (Bessinger 1964), 3,271,895 (Sorensen 1966), 3,564,758 (Willis 1971), and 5,183,430 (Swann 1993). These systems produce models that are susceptible to sagging under their own weight, and to falling apart over time as the elastics stiffen or break. This precludes their use for the construction of permanent display models.

[0013] Other edge to edge connection systems use hook and loop material (hook and loop trade named Velcro). These are described in U.S. Pat. Nos. and 4,836,787 (Boo 1989), 4,884,988 (McMurray 1989). These systems require specific orientation of edges such that hooks and corresponding loops mate properly. This may not always be possible due to the configuration of the model being built. U.S. Pat. No. 3,614,835 (Rice 1971) describes a system of lacing edges together with thread or string. In practice this method is tedious, and only practical for permanent models.

[0014] Finger hinged connection systems use male sexed edge projections which snap together with corresponding female receptacle features. These form pivoting connections between adjacent faces. They are described in U.S. Pat. Nos. 2,057,942 (Fay 1936), 2,776,521 (Zimmerman 1957), 4,055,019 (Harvey 1977), 4,731,041 (Ziegler 1988), 4,792,319 (Suagerko 1988), 5,100,358 (Volgger 1992), 5,137,485 (Penner 1992), 5,472,365 (Engel 1995), 5,707,268 (Outman 1998), 5,833,511 (Outman 1998), 5,895,306 (Cunningham 1999). These designs suffer from the same disadvantages as above; specific orientation is required for parts to mate properly. This may not always be possible due to the configuration of the model being built. Additionally small tolerance errors accumulate as a model takes shape. These can cause failure or breakage of finger projections

SUMMARY

[0015] In accordance with the present geometric model construction system, parts called sides, faces or shape elements, comprise the surfaces of various geometric forms. Other parts called connector strip elements mate various shape elements together along their edges. The shape elements are joined with connector strips in a hinged, slidable union. Two and three-dimensional geometric models are thereby constructed.

OBJECTS AND ADVANTAGES

[0016] Accordingly, several objects and advantages of my geometric toy construction system are as follows:

[0017] a. It is a simple, easily comprehensible construction method.

[0018] b. All parts attach the same way. No individual parts are unique or indispensable.

[0019] c. Any shape element will attach to any other shape element along any edge with any connector strip interchangeably.

[0020] d. The (dihedral) angle between any two hinged shape elements can be continuously varied from zero to 180 degrees or more.

[0021] e. Shape elements may be connected to each other firmly along the entire edge length. This provides a strong bond that can easily survive dropping.

[0022] f. Hinged sliding joints automatically relieve internal stresses which accumulate during construction.

[0023] g. Hinged sliding joints can be adjusted for small size and positional errors of individual shape elements. This facilitates the construction of complex interlocking structures. Geometric models with large numbers of parts may be built.

[0024] h. Completed models can be easily and quickly disassembled. The parts may reused over and over again.

[0025] i. The construction method is hearty. Models assembled for permanent display will remain intact, and not fall apart or degrade over time.

[0026] j. Extremely low start-up and manufacturing costs are possible. This makes the system more accessible and affordable to the educational community. The production of expensive molds is not necessary. Parts can be produced at a price attractive to schools and teachers.

[0027] k. Hinges can be utilized to form dynamic models. The transformation of one geometric form into another may be demonstrated. For instance the same six hinged pyramids fold up one way to form a cube, and another way to form a rhombic dodecahedron. This illustrates that the rhombic dodecahedron having exactly twice the volume of the cube.

[0028] l. The same system builds two-dimensional tessellations, three-dimensional polyhedra, and open frame lattices.

[0029] m. Assembly requires no tools, glues, or other supplies.

[0030] n. More than one edge can be connected to any other edge. Building internal structures can strengthen large and complex models.

[0031] Still further objects and advantages will become apparent from a consideration of the ensuing description and drawings.

DRAWING FIGURES

[0032] In the drawings, closely related figures have the same number but different alphabetic suffixes.

[0033]FIGS. 1A and 1B show nearly completed and fully completed geometric structures built with the system. FIG. 1A shows a model of the small stellated dodecahedron under construction with internal parts visible. FIG. 1 B shows a completed open frame cube.

[0034]FIGS. 2A to 2F show shape elements of various styles. FIG. 2A shows an equilateral triangle shape element. FIG. 2B shows an open frame square shape element. FIG. 2C shows a circular shape element. FIG. 2D shows a curved shape element that is a section of a cylinder. FIG. 2E shows a pentagonal shape element. FIG. 2F shows an irregular shape element with strait edges.

[0035]FIGS. 3A to 3G show various connector strip embodiments. FIG. 3A shows a female double connector strip with a butted hinge-pivot joint. FIG. 3B shows a female double connector strip with a rounded hinge-pivot joint. FIG. 3C shows a male double connector strip with a rounded hinge-pivot joint. FIG. 3D shows a male double connector strip with a v-shaped hinge-pivot joint. FIG. 3E shows a female quadruple connector strip with butted hinge-pivot joints. FIG. 3F shows a female quadruple connector strips with a crossed hinge-pivot joint. FIG. 3G shows a male quadruple connector strip with a crossed hinge-pivot joint.

[0036]FIGS. 4A to 4D show various hinge-leaf embodiments. FIG. 4A shows a hinge-leaf feature with an integral male solid bearing surface. FIG. 4B shows a hinge-leaf feature with an integral male curled bearing surface. FIG. 4C shows a hinge-leaf feature with an integral female bearing surface. FIG. 4D shows a hinge-leaf feature with a separate female bearing surface.

[0037]FIGS. 5A and 5B show assembly detail of a shape element face area and a male tubular bearing surface. FIG. 5A shows the parts before assembly. FIG. 5B shows the parts assembled.

[0038]FIGS. 6A and 6B show assembly detail of a shape element face area and a separate male tubular bearing surface. FIG. 6A shows the parts before assembly. FIG. 6B shows the parts assembled.

[0039]FIGS. 7A and 7B are detail perspective views of assembled hinge-leaf and connector strip embodiments. FIG. 7A shows two male hinge-leaf features mated with a female double connector strip. FIG. 7B shows two female hinge-leaf features mated to a male double connector strip.

NOMENCLATURE IN DESCRIPTION

[0040] Shape element A geometric form such as a polygon or a circle. It may embody a sheet of material or a skeletal wire frame outline. These form the faces of geometric toy models.

[0041] Face area The central area of a shape element. It may be a sheet material or a void bordered by skeletal wire frame edges.

[0042] Connector strip A part used to join adjacent edges of shape elements. Two and three-dimensional geometric models may be formed.

[0043] Hinge-leaf feature A part of a shape element along its perimeter edges. Hinge-leaf features mate with hinge-pivot features of connector strips. Each hinge-leaf feature contains a bearing surface, and is the opposite sex of mating hinge-pivot features.

[0044] Hinge-pivot feature A part of a connector strip that mates with a hinge-leaf feature of a shape element. Each hinge-pivot feature contains a mating surface, and is the opposite sex of mating hinge-leaf features.

[0045] Bearing surface A hinging sliding surface of a hinge-leaf feature along the perimeter of a shape element.

[0046] Mating surface A hinging sliding surface of a hinge-pivot feature of a connector strip element.

[0047] Hinge-pivot joint A structural element permanently joining hinge-pivot features of a connector strip.

[0048] Pivot sweep-arc The range of angles between a shape element and a joined connector strip, or between two adjacent joined shape elements in a model.

REFERENCE NUMERALS IN DRAWINGS

[0049] In the drawings, closely related parts have the same number but different alphabetic suffixes 10 Shape element face area 12 Wire frame element 14 Strait face edge 16 Curved face edge 18 Male mating surface 20 Female mating surface 22 Male tubular bearing surface 24 Male curled bearing surface 26 Male solid bearing surface 28 Female bearing surface 30 Male hinge-leaf feature 32 Female hinge-leaf feature 34 Butted hinge-pivot joint 36 Rounded hinge-pivot joint 38 V-shaped hinge-pivot joint 40 Crossed hinge-pivot joint 42 Female hinge-pivot feature 44 Female double connector strip 46 Edge slot 48 Lengthwise cut 50 Internal finger projections 52 Sliding pivoting bearing surface 54 Attachment hole

DESCRIPTION PREFERRED EMBODIMENT

[0050] A preferred embodiment of the geometric model construction system is comprised of of a variety of shape elements and connector strips. Examples of shape elements are illustrated in FIGS. 2A to 2D. Connector strips of two styles are shown in FIGS. 3A and 3E. These two types of parts (the shape elements, and the connector strips) comprise the basis of the geometric toy construction system. From these parts two and three-dimensional geometric toy models are built up as shown in FIGS. 1A and 1B. FIG. 1A shows a partly completed model of the small stellated dodecahedron. FIG. 1B shows a fully completed model of a cube. Each shape element in the cube is comprised of an identical open wire frame square, one of these is wire frame element 12 b. The edges of adjacent shape elements are held together by twelve identical connector strips. One of these is female double connector strip 44 b. They have c-shaped hinge-pivots designed to admit and grip the wire frames. Alternatively shape elements, FIGS. 2A to 2D, may have a sheet material surface as indicated by face area 10 a, 10 c and 10 d. These shapes are each bordered by a male hinge-leaf feature 30 a, 30 c and 30 d forming a cylindrical bead. This bead is similar in shape and function to the previously described wire frame. FIG. 4A shows this in detail. FIG. 7A shows a portion of two adjacent shape elements in a model. The two shapes are joined together by female double connector strip 44 n. Each shape has a flat surface, one of which is face area 10 n, and hinge-leaves one of which forms male solid bearing surface 26 n. The cylindrical hinge-leaves fit into the corresponding c-shaped hinge-pivots to form bearing interfaces. One of these is sliding pivoting bearing surface 52 n. The hinge-leafs and the hinge-pivots together form a full hinge.

[0051]FIG. 2A shows a triangular shape element. It has face area 10 a and three edges. Each edge comprises an identical hinge-leaf of circular cross-section. One of these is male hinge-leaf feature 30 a. FIG. 2B shows a square shape element. This consists entirely of wire frame element 12 b. It forms an identical hinge-leaf for each of the four edges. One of these is male hinge-leaf feature 30 b. FIG. 2C shows a circular shape element with face area 10 c. The perimeter is curved face edge 16 c. This edge comprises male hinge-leaf feature 30 c. FIG. 2D shows a curved rectangular shape element with face area 10 d. The top and bottom each form an identical edge one of which is curved face edge 16 d. These edges comprise hinge-leaves, one of which is male hinge-leaf feature 30 d. The preferred embodiment includes a variety of shape elements. These are regular polygons having identical edge lengths of about 10 centimeters (4 inches).

[0052]FIG. 3A shows a female double connector strip. It has two identical hinge-pivots, female hinge-pivot feature 42 a is one of these. Each hinge-pivot has a c-shaped cross-section joined in back-to-back fashion by butted hinge-pivot joint 34 a. The interior walls of the hinge-pivot features each form an identical receptacle. Female mating surface 20 a is an example. FIG. 3E shows a female quadruple connector strip. It is comprised of four identical hinge-pivot features each of c-shaped cross-section. They are joined in back-to-back orientation about a central axis. They are joined by four identical structures, one of which is indicated as butted hinge-pivot joint 34 e. The interior wall of each hinge-pivot feature forms an identical receptacle. One of these is female mating surface 20 e. Attachment hole 54 e is an optional aperture, which may be provided for the purpose of suspending a finished model for display.

[0053] In the preferred embodiment some shape elements are wire frames, and others have a solid sheet material face area. Those with solid face areas have integral, one piece molded solid hinge-leaf features. They form solid bearing surfaces with a circular cross-section of about 3 millimeters (about ⅛ inch). They have a face area thickness of about 1.5 millimeters (about {fraction (1/16)} inch). FIG. 4A shows a portion of shape element face area 10 g. Its perimeter edge comprises a hinge-leaf that forms male solid bearing surface 26 g of circular cross-section. FIG. 7A shows a portion of two shape elements. They each have flat surfaces, one of which is face area 10 n. The perimeter edge of each comprises a hinge-leaf feature. Male solid bearing surface 26 n is formed by one of them. Each male hinge-leaf is griped by a female hinge-pivot of connector strip 44 n. Together they comprise a full hinge structure meeting along an interface. Sliding pivoting bearing surface 52 n is an example The c-shaped cross-section of hinge-pivots has an internal diameter slightly less than that the outside diameter of the mating cylindrical hinge-leaves. Female hinge-pivot features have an internal diameter of about 2.75 millimeters (about {fraction (7/64)} inch), and a wall thickness of about 1.5 millimeters (about {fraction (1/16)} inch). In the preferred embodiment, connector strips have a length about equal to the edges of shape elements.

MATERIALS

[0054]FIG. 1A shows a model of the small stellated dodecahedron under construction. The outer triangular shape elements each have a face area made of a sheet material. The model is internally strengthened with pentagonal wire frame elements that add rigidity. In the preferred embodiment shape elements with sheet material face areas are an injection molded tough, rigid plastic material. Examples are shown in FIGS. 2A, 2C and 2D. They may be made of a reinforced polycarbonate with a tensile strength of at least 68 MPa (10,000 lb/in²) and a hardness of at least Rockwell M70. Wire frame elements are made of formed wire sections of solid metal such as mild steel. An example is shown in FIG. 2B. Corners are formed by bending the wire to an internal radius of about 1.5 millimeters (about {fraction (1/16)} inch). The ends are attached to each other by a joining method such as a butt-weld. Grinding forms a continuous perimeter of uniform diameter. Wire frame elements are plastic coated with a material such as a polyvinyl formal with a tensile strength of at least 68 MPa (10,000 lb/in²), and a hardness of at least Rockwell M70. They have a final circular cross-section identical to the previously described hinge-leaf features of shape elements with face areas comprised of sheet material. In the preferred embodiment wire frame elements have a final diameter of about 3 millimeters (about ⅛inch). The connector strips are made of a material that can be repeatedly flexed without fracturing or excessive stretching. Examples are shown in FIGS. 3A and 3E. They are made of a material such as an ether based polyurethane with a tensile strength of at least 54 MPa (7000 lb/in²) and a hardness durometer of shore A85.

ALTERNATIVE EMBODIMENTS

[0055] In the preferred embodiment shape elements have hinge-leaf features with male bearing surfaces. Connector strips have hinge-pivot features with female mating surfaces, as shown in FIG. 7A. In alternative embodiments the sexes are reversed; shape elements have hinge-leaf features with female bearing surfaces, and connector strips have hinge-pivot features with male mating surfaces, as shown in FIG. 7B. FIGS. 2E and 2F show shape elements with female hinge-leaf features. FIG. 2E shows a regular pentagon shape element with face area 10 e. Strait face edge 14 e is one of its five edges and female hinge-leaf feature 32 e is one of its hinge parts. FIG. 2F shows an irregularly shaped polygon with straight edges. It has face area 10 f, and female hinge-leaf feature 32 f is one of four hinge parts. This is shown in greater detail in FIG. 4C. It shows a portion of shape element face area 10 i. The perimeter edge comprises a hinge-leaf which forms female bearing surface 28 i of c-shaped cross-section. FIGS. 3C, 3D, and 3G show various embodiments of connector strips with male mating surfaces 18 c, 18 d, and 18 g respectively. FIG. 3C shows a double connector strip with two identical male mating surfaces, one of which is 18 c the male mating surfaces are connected by a rounded hinge-pivot joint 36 c. FIG. 3D shows a double connector strip with two identical hinge-pivots. One of these forms male mating surface 18 d. V-shaped hinge-pivot joint 38 d connects the hinge-pivots to each other. FIG. 3G shows a quadruple connector strip with four identical hinge-pivots. Male mating surface 18 g is formed by one of them. These are connected to each other by crossed hinge-pivot joint 40 g. The joint has apertures, one of which is attachment hole 54 g. FIG. 4B shows a portion of shape element face area 10 h. The perimeter comprises a hinge-leaf which forms integral male curled bearing surface 24 h of circular cross-section. FIG. 7B shows edges of adjacent shape elements in a model held together by a double connector strip. V-shaped hinge-pivot joint 38 p connects the two identical hinge-pivots, one of which forms male mating surface 18 p. The two shape elements each have a flat surface, one of which is face area 10 p, and hinge-leaves, exemplified by female hinge-leaf feature 32 p. The hinge-leaf features, together with corresponding hinge-pivot features form two interfaces. Sliding pivoting bearing surface 52 p is one of them.

ADDITIONAL EMBODIMENTS

[0056] In further embodiments of the geometric toy construction system, shape elements may be of any geometric shape. They may be solid or wire frame interchangeably. Connector strips may have any number of hinge-pivot features each with identical mating surfaces. Hinge-pivot features may be joined to each other about a central axis by any joint structure that holds them securely. FIG. 3B shows a double connector strip with two identical hinge-pivots, one of which forms female mating surface 20 b. They are connected to each other by rounded hinge-pivot joint 36 b which exhibits mounting hole 54 b. FIG. 3F shows a quadruple connector strip with four identical hinge-pivots. One of these forms female mating surface 20 f. They are connected to each other by crossed hinge-pivot joint 40 f. Hinge-leaf features may be separately manufactured and affixed to shape element face areas. FIG. 4D shows a portion of separate face area 10 j and a portion of a hinge-leaf feature with female mating surface 28 j. Edge slot 46 j is where the face area is to be affixed. FIG. 5A shows a portion of separate face area 10 k. Also shown is a portion of a hinge-leaf feature with male tubular bearing surface 22 k, and lengthwise cut 48 k. FIG. 5B shows the parts assembled. Face area 10 k is inserted through lengthwise cut 48 k into the hinge-leaf feature with male tubular bearing surface 22 k. FIG. 6A shows a portion of separate face area 10 m, and a portion of a hinge-leaf feature with male tubular bearing surface 22 m. The Tube has lengthwise cut 48 m and two identical internal parts, one of which is finger projection 50 m. FIG. 6B shows the parts assembled. Face area 10 m is inserted through lengthwise cut 48 m, past the two internal parts, one of which is finger projections 50 m. these projections grip the face area and lock the hinge-leaf feature in place.

ADVANTAGES

[0057] From the description above, a number of advantages of my geometric model construction system become evident:

[0058] a. Shape elements may be used interchangeably since edges have the same profile and can be connected in place of each other.

[0059] b. Any connector strip may be used to connect any two adjacent edges anywhere in the model desired.

[0060] c. Quadruple connector strips can be used to connect up to four adjacent edges. Shapes inside of shapes may thus be built. Internal structure can be used to give a model rigidity, or extra strength.

[0061] d. The construction of geometric models is robust. Shape elements connect firmly along entire edge lengths. This provides a strong bond that can easily survive dropping.

[0062] e. Some embodiments may be manufactured from commercially available stock tubing and sheet material. This dramatically lowers costs, making the system attractive and affordable to schools.

[0063] f. Economical embodiments may be manufactured from stock commercial tubing. The tubes are cut and slit to form connector strips and separate hinge-leaf features.

[0064] g. Completed models are appropriate for long term display. They may be easily disassembled and the parts may be reused for other models.

[0065] h. Hinges may be used to create dynamic models. These demonstrate the transformation of one geometric form into another.

[0066] i. Separate hinge-leaf parts can be supplied. This allows users to fabricate shape elements not supplied with the system.

OPERATION

[0067] The various shape elements and connector strips are mated together to form geometric models through the repeated use of a single simple procedure. Specifically, a mating surface of a connector strip is held parallel to and against an edge (bearing surface) of a shape element. Gentle but firm force is applied causing the parts to snap together. A hinged union is formed wherein the female surface firmly grips the male surface. By repeating this procedure multiple shape elements may be mated to a connector strip. Also, multiple connector strips may be mated to a shape element. Apply gentle opposing rotational force between two adjacent shape elements mated to a common connector strip. The angle between these shape elements may be adjusted continuously. The angle may be adjusted from zero degrees (flat together like the covers of a closed book) to 180 degrees or more (like the covers of a fully opened book). This gives the adjacent shape elements a combined pivot sweep-arc of at least 180 degrees. In this way a wide variety of two-dimensional tessellations, three-dimensional polyhedra and other geometric forms may be built up.

[0068] In the preferred embodiment, FIG. 7A shows the edges of two adjacent shape elements in a model. They are held together by female double connector strip 44 n. The shape elements have flat surfaces, one of which is face area 10 n, and hinge-leaves, one of which forms male solid bearing surface 26 n. The hinge-leaf features, together with corresponding hinge-pivot features form two interfaces. Sliding pivoting bearing surface 52 n is one. By gentle application of opposing rotational force to the shape elements the angle between them may be adjusted through a pivot sweep-arc of at least 180 degrees.

[0069] Disassembly is accomplished by holding a shape element fixed. Apply gentle but firm force at the end of an adjacent mated connector strip, flexing it away from the shape element. Pulling the shape element and connector strip away from each other releases the hinged union and separates the parts. Repeated application of this action will release all mated parts from each other.

[0070] In alternate embodiments, FIG. 7B shows the edges of adjacent shape elements in a model. They are joined by a double connector strip with v-shaped hinge-pivot joint 38 p. There are two identical hinge-pivots, male mating surface 18 p is formed by one of them. The two shape elements each have a flat surface, one of which is face area 10 p, and hinge-leaves, one of which is female hinge-leaf feature 32 p. The hinge-leaf features, together with corresponding hinge-pivot features form two hinged unions, or interfaces, one of which is sliding pivoting bearing surface 52 p. By gentle application of opposing rotational force to the shape elements the angle between them may be adjusted through a pivot sweep-arc of at least 180 degrees.

CONCLUSIONS, RAMIFICATIONS, AND SCOPE

[0071] Accordingly, the reader will see that the hinged unions formed by this toy geometric model construction system allow for the construction of a wide range of geometric forms. Indeed, the sheer variety and complexity of the two and three-dimensional structures that may be built inspire the imagination.

[0072] While my above description contains many specifications, these should not be construed as limitations on the scope of the present geometric toy construction system, but rather as an exemplification of several embodiments thereof. Many other variations are possible. For example: Shape elements could take the form of spherical or other curved sections. They may be colored, patterned, or labeled to bring out specific properties or features of geometric forms being modeled. Shape elements may be any size that can be manipulated in a practical fashion. They may be any material or combination of materials which allow for the hinging, sliding and gripping action of mating parts described in the appended claims. The face area of shape elements may be detachable from bordering hinge-leaf features. The hinge-leaf features may be supplied as separate attachments for face areas to be fabricated by the end-user. Shape elements may be made of, but are not limited to, the following materials alone or in combination: The polymers polycarbonate, polyester, acetal resin, acrylonitrile-butadiene-styrene (ABS), acrylic, polyamide (nylon), phenol-formaldehyde (phenolic), and polyvinyl cloride (PVC). These polymers may be filled, strengthened, treated, cross-linked or mixed to obtain properties described in the appended claims. Shape elements may also be fabricated from metal, ceramic, wood, paper board or composite materials. They may be textured or smooth, clear or opaque. Connector strips may be made of but are not limited to the following materials: The polymers polyethylene, polypropylene, vinyl, polyamide (nylon) or any other material having the required balance of flexibility and stiffness which allows for the hinging, sliding and gripping action of mating parts described in the appended claims. Shape elements may also have holes of various geometric shapes, these holes edged by hinge-leaf features. Connector strips may be made substantially shorter than the edge lengths of shape elements, and more than one may be used to join two adjacent shape elements. Parts may be made smaller or larger. For example edge lengths of 3 feet (about 1 meter) or more may be used to form structures employed as portable sculptural or ornamental elements.

[0073] Accordingly, the scope of the present geometric toy construction system should be determined not by the embodiments illustrated, but by the appended claims and their legal equivalents. 

I claim:
 1. A geometric toy construction system comprising: A. a plurality of geometric shape elements, each said shape element having a face area and at least one edge, each said edge comprising a hinge-leaf feature, said hinge-leaf and said edge having substantially equal length, the hinge-leaf comprising a substantially cylindrical bearing surface, said bearing surface having a bearing axis and a bearing radius about said bearing axis, the bearing axis being substantially parallel with said edge, and B. a plurality of connector strip elements, each said connector strip having a central axis and having a length up to that of an edge of said shape element, each connector strip being comprised of a plurality of hinge-pivot features, said hinge-pivots being arranged radially about said central axis, each hinge-pivot extending a length substantially equal to that of said connector strip, each hinge-pivot comprising a substantially cylindrical mating surface, said mating surface having a mating axis and a mating radius about said mating axis, said mating radius being substantially similar to said bearing radius and the mating axis being substantially parallel with said central axis, and C. a hinging means of pivotably, slideably, grippingly and removably joining a shape element and a connector strip by mating together a respective hinge-leaf and hinge-pivot, thereby forming a hinged union having a contiguous area between the respective bearing surface and mating surface, said hinged union extending a length substantially equal to that of said connector strip, the joined bearing axis of said shape element being substantially collinear with the corresponding mating axis of said connector strip, the bearing axis and the mating axis together forming a pivot axis, said hinged union having a pivot sweep-arc between said shape element and said connector strip, said sweep-arc being full angular measure of possible positions of the shape element with respect to the connector strip about the common pivot axis of said hinged union, and D. an adjusting means of positioning adjacent shape elements joined to a common connector strip in hinged unions, said adjusting means being accomplished by urging said shape elements rotationally about said pivot axes, and E. a constructing means of pivotably, slideably, grippingly and removably joining a plurality of connector strips with a plurality of shape elements in hinged unions by said hinging means, whereby gripping action of said construction means holds adjacent shape elements of hinged unions firmly in relation to each other, and whereby any hinge-leaf of any shape element connects by said hinging means to any hinge-pivot of any connector strip, and whereby pivoting and sliding motion of said hinging means compensates for cumulative tolerance and positional errors within a model structure, and whereby two-dimensional and three-dimensional geometric toy model structures are built up.
 2. The hinged union of claim 1 wherein A. said hinged union has a said sweep-arc of at least one quarter-turn, and B. adjacent said hinged unions of a common connector strip have said sweep-arcs that intersect in space and together subtend an arc greater than one half-turn, whereby two adjacent shape elements, each joined to a common connector strip in hinged unions by said constructing means form an included angle that continuously varies from naught to one half-turn by said adjustment means, and whereby different shape elements are joined in various combinations to build a full range of polyhedron models.
 3. The shape element of claim 1 wherein the form of the shape element is selected from the group consisting of A. polygon and B. circle and C. shape with curved edges and D. ring shape E. cylindrical shell and F. spherical shell section, whereby different shape elements may be combined to form a wide variety of model structures.
 4. The shape element of claim 1 further comprising A. a face area as a sheet element, and B. a bead fabricated as an integral part of said shape element, whereby said shape element is fabricated as a single part by suitable means, and whereby fabrication of the shape element is simplified.
 5. The shape element of claim 1 further comprising A. a face area as a void, and B. a skeletal frame forming a continuous circuit and having a substantially circular cross-section, said skeletal frame comprising a plurality of hinge-leaves, whereby said hinge union means and said constructing means are employed to build up open frame models revealing interior structure, and whereby model structures are internally strengthened with a plurality of said skeletal frames.
 6. The connector strip of claim 1 further comprising a double hinge strip, said double hinge strip being comprised of two said sleeves of c-shaped cross-section affixed in a back-to-back relationship substantially along said central axis, whereby each of two shape elements are joined by said hinging means, and a multiplicity of shape elements are joined by said constructing means.
 7. The connector strip of claim 1 further comprising a quad hinge strip, said quad hinge strip being comprised of four said sleeves of c-shaped cross-section affixed in a back-to-back relationship substantially along said central axis, said sleeves being joined together in a substantially radial fashion about said central axis, whereby each of four shape elements are joined to a single quad hinge strip by said hinging means, and a multiplicity of shape elements are joined by said constructing means, and whereby model structures are built up with intersecting planes, and whereby model structures are strengthened with internal elements.
 8. A geometric toy construction system comprising: A. a plurality of geometric shape elements, each said shape element having a face area and at least one edge, each edge comprising a bead, said bead extending substantially the length of said edge and, the bead being of a substantially cylindrical form, the surface of the bead comprising a cylindrical bearing surface, said bearing surface having a bearing axis and a bearing radius about said bearing axis, the bearing axis being substantially parallel with said edge, and B. a plurality of connector strip elements, each said connector strip having a central axis and having a length up to the length of an edge of said shape element, each connector strip being comprised of a plurality of sleeves of substantially identical form, each said sleeve is of c-shaped cross-section and is arranged radially about said central axis, each sleeve extending a length substantially equal to that of said connector strip, the inside surface of each said sleeve comprising a substantially cylindrical mating surface, each said mating surface having a mating axis and a mating radius about said mating axis, said mating radius being substantially similar to said bearing radius and the mating axis being substantially parallel with said central axis, and C. said bead being made of a suitably tough and hard material as to be gripped firmly by said sleeve, the sleeve being made of a suitably resilient material as to admit and grip the bead, and D. a hinging means of pivotably, slideably, grippingly and removably joining a shape element and a connector strip by mating together a respective bead and sleeve thereby forming a hinged union having a contiguous area between the respective bearing surface and mating surface, said hinged union extending substantially the length of said connector strip, the joined bearing axis of said shape element being substantially collinear with the corresponding mating axis of said connector strip, the bearing axis and the mating axis together forming a pivot axis, said hinged union having a pivot sweep-arc, said sweep-arc defining the full range of pivot motion between the shape element and the connector strip about the common pivot axis of said hinged union, and E. an adjusting means of positioning adjacent shape elements joined to a common connector strip in hinged unions, said adjusting means being accomplished by urging said shape elements rotationally about said pivot axes, and F. a constructing means of pivotably, slideably, grippingly and removably joining a plurality of said connector strips with a plurality of said shape elements in hinged unions by said hinging means, whereby the gripping action of said construction means holds adjacent shape elements of said hinged unions firmly in relation to each other, and whereby the pivoting and sliding motion of a hinged union compensates for cumulative tolerance and positional errors within a model structure, and whereby any bead of any shape element connects by said hinging means to any sleeve of a model structure under construction, and whereby two-dimensional and three-dimensional geometric toy model structures are built up.
 9. The hinged union of claim 8 wherein A. said hinged union has a said sweep-arc of at least one quarter-turn, and B. adjacent said hinged unions of a common connector strip have said sweep-arcs that intersect in space and together subtend an arc greater than one half-turn, whereby two adjacent shape elements, each joined to a common connector strip in hinged unions by said constructing means form an included angle, said angle continuously varies from naught to one half-turn by said adjusting means, and whereby different shape elements are joined in various combinations to form a full range of polyhedron models.
 10. The shape element of claim 8 wherein the form of the shape element is selected from the group consisting of A. polygon and B. circle and C. shape with curved edges and D. ring shape and E. cylindrical shell and F. spherical shell section, whereby different shape elements may be combined to form a wide variety of model structures.
 11. The shape element of claim 8 further comprising C. said face area as a sheet element, and D. said bead fabricated as an integral part of said shape element, whereby said shape element is fabricated as a single part by suitable means, and whereby fabrication of the shape element is simplified.
 12. The shape element of claim 8 further comprising A. said face area as a void, and B. said bead a s a skeletal frame forming a continuous circuit and having a substantially circular cross-section, whereby said hinge union means and said constructing means are employed to build up open frame models revealing interior structure, and whereby models are internally strengthened with a plurality of said skeletal frames.
 13. The connector strip of claim 8 further comprising a double hinge strip, said double hinge strip being made from commercially available extruded twin-tubing, said twin-tubing being comprised of two substantially tubes of circular cross-section joined together, said twin-tubing being sectioned, forming two said sleeves of c-shaped cross-section contiguously affixed in a back-to-back relationship substantially along said central axis, whereby each of two shape elements are joined by said hinging means, and a plurality of shape elements are joined by said constructing means, and whereby geometric toy model kits are fabricated with economical commercially available standard parts with minor modification.
 14. The connector strip claim 8 further comprising a quad hinge strip, said quad hinge strip being made from commercially available extruded quadruple tubing said quadruple tubing being comprised of four substantially similar tubes of circular cross-section joined together in a substantially radial fashion about said central axis, said quadruple tubing being sectioned forming four said sleeves of c-shaped cross-section contiguously affixed in a back-to-back relationship substantially along said central axis whereby each of four shape elements are joined to a single quad hinge strip by said hinging means, and a plurality of said shape elements are joined by said constructing means, whereby model structures with intersecting planes are built up, and whereby model structures are strengthened with internal elements.
 15. The shape element of claim 8 further comprising A. said face area as a sheet element having a perimeter substantially the same as heretofore said perimeter and having edges that are substantially the same as heretofore said edges, said sheet element is made of a material selected from the group consisting of a. paper tag stock and b. polymer sheet and c. cardboard stock and d. wood panel and e. metal sheet and f. glass pane and g. ceramic wafer and h. Composite material, B. said bead being a separate part attached to said sheet element by appropriate means, the bead comprising a cylindrical tube with a single radial through-cut parallel to said bearing axis, said through-cut substantially extending the length of said cylindrical tube, the cylindrical tube being made of a suitably resilient material as to admit and grip said sheet element along said edge, and C. a mating means of joining said cylindrical tube and said sheet element by urging said edge of the sheet element into said through-cut in the cylindrical tube substantially along the length of the through-cut, whereby a shape element is fabricated economically with commercially available standard parts requiring only minor modification, and whereby an end-user may fabricate and use new shape elements to supplement those supplied with the system.
 16. A geometric toy construction system comprising: A. a plurality of geometric shape elements, each said shape element having a face area and at least one edge, each edge comprising a sleeve of c-shaped cross-section, said sleeve extending substantially the length of said edge and, the inside surface of the sleeve comprising a substantially cylindrical bearing surface, said bearing surface having a bearing axis and a bearing radius about said bearing axis, the bearing axis being substantially parallel with said edge, and B. a plurality of connector strip elements each said connector strip having a central axis and a length up to the length of an edge of said shape element, each connector strip being comprised of a plurality of cylindrical beads of substantially identical form, each said bead is arranged radially about said central axis, each bead extending substantially the length of said connector strip, the surface of each said bead comprising a substantially cylindrical mating surface, each said mating surface having a mating axis and a mating radius about said mating axis, said mating radius being substantially similar to said bearing radius and the mating axis being substantially parallel with said central axis, and C. said bead being made of a suitably tough and hard material as to be gripped firmly by said sleeve, the sleeve being made of a suitably resilient material as to admit and grip the bead, and D. a hinging means of pivotably, slideably, grippingly and removably joining a shape element and a connector strip by mating together respective bead and sleeve thereby forming a hinged union having a contiguous area between respective bearing surface and mating surface, said hinged union extending substantially the length of said connector strip, the joined bearing axis of said shape element being substantially collinear with the corresponding mating axis of said connector strip, the bearing axis and the mating axis together forming a pivot axis, said hinged union having a pivot sweep-arc, said sweep-arc defining the full range of pivot motion between the shape element and the connector strip about the common pivot axis of said hinged union, and E. an adjusting means of positioning adjacent shape elements joined to a common connector strip in hinged unions, said adjusting means being accomplished by urging said shape elements rotationally about their joined pivot axes, and F. a constructing means of pivotably, slideably, grippingly and removably joining a plurality of said connector strips with a plurality of said shape elements in hinged unions by said hinging means, whereby the gripping action of said construction means holds adjacent shape elements of said hinged unions firmly in relation to each other, and whereby the pivoting and sliding motion of said hinging means compensates for cumulative tolerance and positional errors within a model structures, and whereby any bead of any shape element connects by said hinging means to any sleeve of a model structures under construction, and whereby two-dimensional and three-dimensional geometric toy model structures are built up.
 17. The hinged union of claim 16 wherein A. said hinged union having a said sweep-arc of at least one quarter-turn, and B. adjacent said hinged unions of a common connector strip have said sweep-arcs that intersect in space and together subtend an arc greater than one half-turn, whereby two adjacent shape elements, each joined to a common connector strip in hinged unions by said constructing means form an included angle that continuously varies from naught to one half-turn by said adjusting means, and whereby different shape elements are joined in various combinations to build a full range of polyhedron models.
 18. The shape element of claim 16 wherein the form of the shape element is selected from the group consisting of G. polygon and H. circle and I. shape with curved edges and J. ring shape and K. cylindrical shell and L. spherical shell section.
 19. The connector strip of claim 16 further comprising a double hinge strip, said double hinge strip being comprised of two said cylindrical beads affixed in a back-to-back relationship substantially along said central axis, whereby two shape elements are joined to a common connector strip by said hinging means, and a plurality of shape elements are joined by said constructing means, and whereby geometric toy model kits are fabricated with economical commercially available standard parts with minor modification.
 20. The connector strip of claim 16 further comprising a quad hinge strip said quad hinge strip being comprised of four substantially similar cylinders of circular cross-section joined together in a substantially radial fashion about said central axis, said cylinders affixed in a back-to-back relationship substantially along said central axis, whereby each of four shape elements are joined by said hinging means, and a multiplicity of shape elements are joined by said constructing means, whereby model structures with intersecting planes are built up, and whereby model structures are strengthened with internal elements. 